Week 5

Oh it's been quite a week. For one, we had a little heat wave in New York. The funny thing is, I spent the hottest part of the day in the north lab where the cryostat is, so it get's pretty cold. Then I'd head straight to the SAE shop via the CEPSR and Mudd bridges, so I wouldn't need to take a step outside. Anyway, in other news: the Heat dominated the Thunder to win the 2012 NBA title. The Kings beat the Devils to take the Stanley Cup. Audi dominated the 24 hours Le Mans race. Portugal and Spain reach the Eurocup semifinals. Mets and Yankees duke it out. Vettel takes pole at the European Grand Prix. Well, a lot has happened.

The surf review for the weekend: flat. So I did some longboarding on Saturday (and stepped on a crab), and on Sunday, I actually tried Stand Up Paddle. It was a bit choppy, so instead of standing up, I spent most of my time kneeling. It was exhausting but fun. I spent about two straight hours just floating way outside the lineup, basking in the glory of the sun and solitude, while savoring the envy of the multitude of beachgoers stuck on land. The most tiring was simply lugging the board six blocks to return it. That thing is massive, and attracts maybe too much attention.

Anyway, last week has seen some decent progress in the lab. I was able to successfully solder onto a board the triac, heat sink, opto-isolator and necessary resistors to make an effective "switch." The triac is told by the temperature controller whether to open or close the circuit (the heat plate), and the opto-isolator separates the controller+triac loop from the heat plate loop, so the temperature controller is protected.

The other thing was learning to use Labview to get a temperature readout from the LM35 using the Analog to Digital Converter (ADC). It took a while, but with some help from Ross, it worked out pretty well. The LM35 provided a linear relationship between voltage and temperature, and the chart readout taught me a little about pink noise (1/f). As the temperature increases, the noise level would decrease with 1/f.

I put in the orders for the MUX chips as well. 16-pin DIP 8x1 Multiplexers. For the 32 LM35s, I will need about four chips (8x4=32).

So some things on the agenda this week:
Find problem with "switch" board. It seems the triac and opto-isolator are working just fine, so it could be a problem with the PI controller.
Continue with Labview stuff.
Drill and tap holes for LM35s.
Test MUX chips if they arrive.